Temperature and frequency dependence of dielectric relaxation and AC electrical conductivity in p-Si/CuPc hybrid photodiode

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2018-09, Vol.124 (9), p.1-13, Article 591
• Main Authors: Shehata, M. M., Abdelhady, K.
• Format: Article
• Language: English
• Subjects: Aluminum; Applied physics; Characterization and Evaluation of Materials; Condensed Matter Physics; Current carriers; Dielectric relaxation; Electrical resistivity; Heterojunctions; Machines; Manufacturing; Materials science; Minority carriers; Nanotechnology; Optical and Electronic Materials; Photodiodes; Physics; Physics and Astronomy; Processes; Silicon substrates; Spectrum analysis; Surfaces and Interfaces; Temperature dependence; Thin Films
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-018-2006-6

Thermal evaporation technique has been used to fabricate a hybrid heterojunction Al/p-Si/CuPc/Au photodiode by deposition of a CuPc thin film onto a p-Si substrate. The dark I – V curves exhibit diode-like behavior. The impedance characteristics of the Al/p-Si/CuPc/Au hybrid heterojunction were examined using complex impedance spectroscopy. In the investigated device, the activation energies have been obtained from Arrhenius plotting of two relaxation processes. The Cole–Cole plot and the electrical conductivity were reported and showed that the heterostructure possesses a negative temperature coefficient of resistance. The excess minority carrier lifetimes, the diffusion coefficients and the mobilities of charge carriers at two interfaces were calculated and interpreted. From the impedance spectra analysis, the band profile of the studied device can be fully determined.